"I will not aspire to nor accept -- I repeat, I will not aspire to nor accept -- the post of President of the Council of State and Commander in Chief," read a letter signed by Castro published early Tuesday in the online edition of the Communist Party daily Granma.

The announcement effectively ends the rule of the 81-year-old Castro after almost 50 years, positioning his 76-year-old brother Raul for permanent succession to the presidency. Fidel Castro temporarily ceded his powers to his brother on July 31, 2006, when he announced that he had undergone intestinal surgery.

Since then, the elder Castro has not been seen in public, appearing only sporadically in official photographs and videotapes and publishing dense essays about mostly international themes as his younger brother has consolidated his rule.

Fidel is the same age as my mother-in-law, and both are frail and ailing. Raul is widely rumored to be maricon, though he has a daughter placed in Cuban government. Raul's wife Vilma Espin, who was instrumental in decriminalizing homosexuality in Cuba in 1979, died last June at the age of 77.